Method for transmitting video picture, device for sending video picture, and video call method and device

Abstract

Embodiments of this disclosure provide a method for transmitting a video picture, a device for sending a video picture, and a video call method and device, where the video picture includes a plurality of video frames. According to the method for transmitting a video picture, the plurality of video frames are encoded to obtain an encoded bitstream, where the bitstream includes at least information indicating inter-frame reference relationships. In this application, each of N frames preceding to a current frame references a forward long-term reference (LTR) frame that has a shortest temporal distance to each of the preceding N frames, and the forward LTR frame is an encoded video frame marked by a transmit end device as an LTR frame.

What is claimed is: 
     
       1. A method for transmitting a video picture, wherein the video picture comprises a plurality of video frames, and the method comprises:
 encoding the plurality of video frames to obtain an encoded bitstream, wherein the encoded bitstream comprises information indicating inter-frame reference relationships; and 
 sending the encoded bitstream, wherein the information indicating the inter-frame reference relationships comprises:
 information about an inter-frame reference relationship of a current frame, wherein the information about the inter-frame reference relationship of the current frame indicates that the current frame references a target forward long-term reference (LTR) frame that has a shortest temporal distance to the current frame, the target forward LTR frame is a forward LTR frame for which a transmit end device receives an acknowledgment message from a receive end device, and the acknowledgment message corresponds to the target forward LTR frame; and 
 information about inter-frame reference relationships of N frames preceding to the current frame, wherein the information about the inter-frame reference relationships of the N frames preceding to the current frame indicates that each of the preceding N frames references a forward LTR frame that has a shortest temporal distance to each of the preceding N frames. 
 
 
     
     
       2. The method according to  claim 1 , wherein the information indicating the inter-frame reference relationships further comprises information about inter-frame reference relationships of M frames following the current frame, and the information about the inter-frame reference relationships of the M frames following the current frame indicates that each of the following M frames references a previous frame of each of the following M frames, wherein N and M are positive integers. 
     
     
       3. The method according to  claim 2 , further comprises:
 determining, by the transmit end device, a value of M based on a quantity of video frames comprised per unit time. 
 
     
     
       4. The method according to  claim 3 , further comprises:
 determining, by the transmit end device, a LTR frame marking interval D based on network status information fed back by the receive end device, wherein the network status information comprises one or more of a network packet loss rate, an available network bandwidth, and a network round-trip time (RTT). 
 
     
     
       5. The method according to  claim 3 , wherein a LTR frame marking interval D is used by the transmit end device to mark an LTR frame. 
     
     
       6. The method according to  claim 1 , wherein the information indicating the inter-frame reference relationships further comprises information about inter-frame reference relationships of M frames following the current frame, and the information about the inter-frame reference relationships of the M frames following the current frame indicates that each of the following M frames references a forward LTR frame that has a shortest temporal distance to each of the following M frames, wherein N and M are positive integers. 
     
     
       7. The method according to  claim 1 , further comprises:
 determining, by the transmit end device, a value of N based on coding quality of n frames preceding to the current frame, wherein n<N. 
 
     
     
       8. The method according to  claim 1 , wherein the method is applied to an electronic device having a display and a picture collector, wherein the method further comprises:
 in response to determining that a first operation of a first user for requesting a video call with a second user, establishing a video call connection between the first user and the second user; and 
 collecting, by using the picture collector, a video picture of an environment comprising the first user, wherein the video picture comprises a plurality of video frames. 
 
     
     
       9. A device for sending a video picture, wherein the video picture comprises a plurality of video frames, and the device comprises:
 an encoder, configured to encode the plurality of video frames to obtain an encoded bitstream, wherein the encoded bitstream comprises information indicating inter-frame reference relationships; and 
 a transmitter, configured to send the encoded bitstream, wherein the information indicating the inter-frame reference relationships comprises:
 information about an inter-frame reference relationship of a current frame, wherein the information about the inter-frame reference relationship of the current frame indicates that the current frame references a target forward long-term reference (LTR) frame that has a shortest temporal distance to the current frame, the target forward LTR frame is a forward LTR frame for which a transmit end device receives an acknowledgment message from a receive end device, and the acknowledgment message corresponds to the target forward LTR frame; and 
 information about inter-frame reference relationships of N frames preceding to the current frame, wherein the information about the inter-frame reference relationships of the N frames preceding to the current frame indicates that each of the preceding N frames references a forward LTR frame that has a shortest temporal distance to each of the preceding N frames. 
 
 
     
     
       10. The device according to  claim 9 , wherein the information indicating the inter-frame reference relationships further comprises information about inter-frame reference relationships of M frames following the current frame, and the information about the inter-frame reference relationships of the M frames following the current frame indicates that each of the following M frames references a previous frame of each of the following M frames, wherein N and M are positive integers. 
     
     
       11. The device according to  claim 10 , wherein the encoder determines a value of M based on a quantity of video frames comprised per unit time. 
     
     
       12. The device according to  claim 11 , wherein an LTR frame marking interval D has a function relationship with N and M. 
     
     
       13. The device according to  claim 10 , wherein the information indicating the inter-frame reference relationships further comprises information about inter-frame reference relationships of L frames, wherein L=(M1+1)+(M2+1)+ . . . +(Mn+1), the L frames temporally follow the M frames, the information about the inter-frame reference relationships of the L frames indicates that a first frame in (Mn+1) frames references a target forward LTR frame that has a shortest temporal distance to the first frame, and indicates that each frame after the first frame in the (Mn+1) frames references a previous frame of each frame after the first frame, L is a positive integer, and n is a positive integer greater than or equal to 1. 
     
     
       14. The device according to  claim 13 , wherein an LTR frame marking interval D has a function relationship with N and L. 
     
     
       15. The device according to  claim 9 , wherein the information indicating the inter-frame reference relationships further comprises information about inter-frame reference relationships of M frames following the current frame, and the information about the inter-frame reference relationships of the M frames following the current frame indicates that each of the following M frames references a forward LTR frame that has a shortest temporal distance to each of the following M frames, wherein N and M are positive integers. 
     
     
       16. The device according to  claim 9 , wherein the encoder determines a value of N based on coding quality of n frames preceding to the current frame, wherein n<N. 
     
     
       17. The device according to  claim 9 , wherein the encoder determines an LTR frame marking interval D based on network status information fed back by the receive end device, wherein the network status information comprises one or more of a network packet loss rate, an available network bandwidth, and a network round-trip time (RTT). 
     
     
       18. A device for receiving a video picture, wherein the video picture comprises a plurality of video frames, and the device comprises:
 a decoder, configured to parse a bitstream to obtain information indicating inter-frame reference relationships, wherein the information indicating the inter-frame reference relationships comprises:
 information about an inter-frame reference relationship of a current frame, the information about the inter-frame reference relationship of the current frame indicates that the current frame references a target forward long-term reference (LTR) frame that has a shortest temporal distance to the current frame; and 
 information about inter-frame reference relationships of N frames preceding to the current frame, wherein the information about the inter-frame reference relationships of the N frames preceding to the current frame indicates that each of the preceding N frames references a forward LTR frame that has a shortest temporal distance to each of the preceding N frames; 
 
 the decoder is further configured to reconstruct the plurality of video frames, wherein the reconstructing the plurality of video frames comprises reconstructing a current video frame based on a reference frame of the current frame; and 
 a display device, configured to display the video picture. 
 
     
     
       19. The device according to  claim 18 , wherein the information indicating the inter-frame reference relationships further comprises information about inter-frame reference relationships of M frames following the current frame, and the information about the inter-frame reference relationships of the M frames following the current frame indicates that each of the following M frames references a previous frame of each of the following M frames, wherein N and M are positive integers. 
     
     
       20. The device according to  claim 18 , wherein the information indicating the inter-frame reference relationships further comprises information about inter-frame reference relationships of M frames following the current frame, and the information about the inter-frame reference relationships of the M frames following the current frame indicates that each of the following M frames references a forward LTR frame that has a shortest temporal distance to each of the following M frames, wherein N and M are positive integers.